By dealing CrCl3∙3THF with the corresponding ligands (L1–L5), an array of fluoro-substituted chromium (III) chlorides (Cr1–Cr5) bearing 2-[1-(2,4-dibenzhydryl-6-fluoro- phenylimino)ethyl]-6-[1-(arylimino)ethyl]pyridine (aryl = 2,6-Me2Ph Cr1, 2,6-Et2Ph Cr2, 2,6-iPr2Ph Cr3, 2,4,6-Me3Ph Cr4, 2,6-Et2-4-MePh Cr5) was synthesized in good yield and validated via Fourier Transform Infrared (FT-IR) spectroscopy and elemental analysis. Besides the routine characterizations, the single-crystal X-ray diffraction study revealed the solid-state structures of complexes Cr2 and Cr4 as the distorted-octahedral geometry around the chromium center. Activated by either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all the chromium catalysts exhibited high activities toward ethylene polymerization with the MMAO-promoted polymerizations far more productive than with MAO (20.14 × 106 g (PE) mol−1 (Cr) h−1 vs. 10.03 × 106 g (PE) mol−1 (Cr) h−1). In both cases, the resultant polyethylenes were found as highly linear polyethylene waxes with low molecular weights around 1–2 kg mol−1 and narrow molecular weight distribution (MWD range: 1.68–2.25). In general, both the catalytic performance of the ortho-fluorinated chromium complexes and polymer properties have been the subject of a detailed investigation and proved to be highly dependent on the polymerization reaction parameters (including cocatalyst type and amount, reaction temperature, ethylene pressure and run time).

中文翻译：

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通过不对称 2,4-双（亚氨基）吡啶基氯化铬统一高线性聚乙烯蜡的分子量


通过用相应的配体 (L1–L5) 处理 CrCl3∙3THF，得到一系列带有 2-[1-(2,4-二二苯甲基-6-氟-苯基亚氨基) 的氟取代氯化铬 (III) (Cr1–Cr5)乙基]-6-[1-(芳基亚氨基)乙基]吡啶（芳基 = 2,6-Me2Ph Cr1、2,6-Et2Ph Cr2、2,6-iPr2Ph Cr3、2,4,6-Me3Ph Cr4、2,6 -Et2-4-MePh Cr5) 以良好的产率合成，并通过傅里叶变换红外 (FT-IR) 光谱和元素分析进行​​验证。除了常规表征之外，单晶 X 射线衍射研究还揭示了配合物 Cr2 和 Cr4 的固态结构，即围绕铬中心的扭曲八面体几何形状。通过甲基铝氧烷 (MAO) 或改性甲基铝氧烷 (MMAO) 活化，所有铬催化剂都表现出对乙烯聚合的高活性，其中 MMAO 促进的聚合比 MAO 的聚合效率高得多 (20.14 × 106 g (PE) mol−1 (Cr) h−1 与 10.03 × 106 g (PE) mol−1 (Cr) h−1)。在这两种情况下，所得聚乙烯都是高度线性的聚乙烯蜡，具有约 1-2 kg mol−1 的低分子量和窄的分子量分布（MWD 范围：1.68-2.25）。一般来说，邻氟化铬络合物的催化性能和聚合物性能都已成为详细研究的主题，并被证明高度依赖于聚合反应参数（包括助催化剂类型和用量、反应温度、乙烯压力和运行时间）。时间）。